Gas turbine engines are used to power aircraft, watercraft, power generators, and the like. Gas turbine engines typically include a compressor, a combustor, and a turbine. The compressor compresses air drawn into the engine and delivers high pressure air to the combustor. In the combustor, fuel is mixed with the high pressure air and is ignited. Products of the combustion reaction in the combustor are directed into the turbine where work is extracted to drive the compressor and, sometimes, an output shaft. Left-over products of the combustion are exhausted out of the turbine and may provide thrust in some applications.
Air is drawn into the engine through an air inlet and communicated to the compressor via an air-inlet duct. In some operating conditions, particles may be entrained in the air such as dust, sand, or liquid water and may be drawn into the air inlet and passed through the air-inlet duct to the compressor. Such particles may impact components of the compressor and turbine causing unintended wear. This unintended wear may decrease power output of the engine, shorten the life span of the engine, and lead to increased maintenance costs and increased down time of the engine.
One method of separating particles from air entering the compressor has been by inertial particle separation. Inertial particle separation uses the inertia of the particles to separate the particles from the air. As the air stream moves through the air-inlet duct, the air moves along a serpentine flow path and enters an engine channel of the air-inlet duct while the particles move along a generally linear travel path and enter a scavenge channel included in the air-inlet duct. In some instances, particles may deviate from the generally linear travel path and enter the engine channel rather than the scavenge channel. Particles may deviate from the generally linear travel path due separation of flow from an outer wall of the air-inlet duct leading to recirculation of the particles and/or other fluid flow phenomenon upstream of the scavenge channel.